1. Field
The present disclosure generally relates to optical signal processing and, in particular, relates to detection and identification of optical systems through analysis of reflected signals.
2. Description of the Related Art
Soldiers in combat situations have long since faced the danger of snipers firing from concealed locations. Finding a sniper can be difficult even once the sniper has fired, given that a sniper may be 200-1200 meters away. This is even more difficult in urban battlefields where locating the source of a shot by ear is hampered by the echoes of the shot and the high level of background noise. Fixed encampments are susceptible to a sniper attack at any time. The preferred solution for anyone in hostile territory is to identify the presence of a sniper before they fire their first shot.
Several companies have produced sniper detection systems based on acoustic detection of the bullet's passage through the air or the muzzle blast of the rifle. These are only effective after the shot is fired, however, and offer no capability to detect surveillance by hostile forces prior to an attack or hostile forces that are monitoring a roadside bomb to trigger it when it can do the most damage.
Several companies have also produced sniper detection systems based on optical detection of the lenses of surveillance binoculars or rifle scopes. In some systems, a laser is reflected by optical systems to a receiver, whereupon an operator manually assesses the threat.
Disadvantages of the current approaches include a slow rate of scanning the environment, where it can take several minutes to scan a 120 degree sector, and the use of only the intensity of the reflection to identify possible threats which leads to a high percentage of false warnings. In assessing potential threats manually, it may be difficult for an operator to identify an observer or sniper who may be well camouflaged. In addition, there may be a lag of several minutes between the detection of a potential threat and assessment of the threat by the operator, leaving personnel within the protected area at risk during this delay.